The Clinical Core, located at the University of Washington Virology Research Clinic (UW-VRC), has been devoted to genital herpes simplex virus (HSV) research since it was founded nearly 40 years ago. Specific Aims of the Clinical Core are 1) To recruit, enroll, and retain participants into research protocols from defined populations, including participants with mild and severe genital HSV-2 phenotypes for Projects 2 & 3, and participants with primary genital HSV-1 infection for Project 4; 2) To ensure integrity of data collected for Projects 2, 3, and 4 by adhering to study procedures and promoting the highest standards of human subjects research, including adherence to Good Clinical Practice; and 3) To obtain clinical specimens required for virologic and immunologic investigations including swabs from mucosal sites for Projects 3 & 4, genital biopsies for Projects 2 & 3, and blood and detailed clinical histories for Projects 2, 3, & 4. In addition, the Clinical Core will be responsible for training staff in Thika, Kenya, for Project 1. The Clinical Core has pioneered intensive genital specimen collection to define the natural history of HSV shedding and host-pathogen interactions. Our track record shows that we can retain participants in these intensive protocols which involve daily self-collected genital swabs. We have enrolled nearly 1000 participants in such studies. We have developed expertise in collection of genital biopsies, and we can safely collect serial genital biopsies from participants for detailed immunological and pathogenesis studies proposed in Scientific Projects. The Clinical Core collaborates closely with the Laboratory Core and the Statistical Core to evaluate new HSV testing methods, such as HSV PCR, and to answer novel questions in HSV research and we will continue to do so in this POI. The Clinical Core will also ensure that all clinical research is conducted with the highest ethical standards and with adherence to Good Clinical Practice (GCP).